Hollow milling machine



March 4, v GREY HOLLOW MILLING MACHINE.

Filed March 15', 1945 4 Sheets-Sheet l AT RNEY March 4, V, GREY HOLLOWMILLING MACHINE l 4 sheets-sheet 2 Filed March l5, 1943 man w vm 9 KMarch 4, 1947. v GREY 2,416,749

HOLLOW MILLING MACHINE Filed March-15, 1945 4 Sheets-Sheet 3 COOLNTSTART O y 0 SPINDLE INVENTOR vlcToR GREY March 4, v GREY.

HQLLOW MILLINGv MACHINE` Filed March 15, 1945 4 Sheets-Sheet 4 INVENToRVICTOR GREY .-low shafts or sleeves.

Patented Mar. 4,1947

s Pimm-f- .HOLLOW MILLING MACHINE Victor Grey, Chicago, Ill., assignerVto Teletype Corporation, Chicago, Ill., a corporation of `DelawareApplication Manch 415, 1943, 'Serial No. 479,230

i1 .The `present -invention relates to automatic milling machines and.more .particularly to ma- ...chines of this general .class which areadapted Ato the .production of several different Vautomatic millingoperations.

In various types of printing telegra-phapparatus there .are employed.tape .feed .sprocket wheels having minute 4feed teeth .or pins ofspecial .formation. These wheels `are utilized `tor the ad* vancement.of control forms .by propelling .them through engagement with. ralongitudinal row of .perforations .provided .centrally thereof. Consistlent with particular requirements, the .shape and number of the tapefeed :tee'thon various -types .of .sprocket wheels may vary as specificreduirements indicate and according-ly it is :herewith lcontemplated `toprovide .an automatic hollow milling .apparatus having an `adjustable:indexing device especially adaptable to the ser-vice of in -dexing aSprocket .blank holding spindle .so -:as to provide for predetermined4variati-ons in ther-inm- .ber 4and formationcf said 'sprocket teeth.

In the manufacture .of telegraph apparatus,

.sprocket wheels of this class are most .frequently Aintegral with solidsupporting Yshafts or'with hol- .Accordingly means are provided, inA:association with-the vpresent invention, ywhereby several types o'f''sprocket blank holding apparatus, designed to. :engage .either 4sleeveor .spindle sprocket vwheel blankspmay 'be 1 Claim. (C1. 90414) whichperform successively during the indexing and tool feeding Ioperaticmswhich together com'- pr-iseithe steps of milling a-num'ber ofperipherally .disposedsprocket feedteeth in a cylindrical blank or wheelyso that while the blank -is undergoing a full revolution, apredetermined number of equally spaced tooth yforming operations arevcom- `-rrla-ndrel and replaces it with a blank lpiece Apart -uponAwhich lthe `succession `-of milling operations are thereafterperformed. f

For a comprehensive understanding of the present invention reference`will now ib'e had to the following "detailed specication :zand fto.#the va;cccmpanying drawings ywherein similar reference numeralsdesignate corresponding parts throughout and in which,

Fig. -1 `is anelectricalcircuit diagram illustrating the severalVoperating motors :and supervi- :sory `control contacts .inciden-t `tothe electrical control system `of the present invention;

Fig. 2 `is a plan `view fof the mechanical `struc-- rture rembody-ingrcertain features of the present invention; 1

Fig. 3 kis -a slightly -enlargedside .elevational View of a portion ofthe apparatus featured fin Rig. .2 `witha portion of the supporting hasepartially in section;

Fig. 4 is an enlarged detail .sectional view ytaken .approX-imatelyon.line 4-4=of Fig. .2;

Fig. .5 is .a longitudinal sectional yiew taken .approximately-on line 55 of Fig. .2 .featuringthe .-index-ingshaft .and supporting xtureforonetyp of sprocket .feed wheel; y f j Fig. 6 is .an enlargedsectionalview takenap.- proximately online -G-K-B .of lFig. ,2 Eand illustratingthe .tool holding chuck in .two positions; n

Fig. 7 is a .detailed perspective view-of one .type Aof sprocket wheelpiece partwhose .feed teeth may .be formed with the .apparatus featuredin Fig.,9.;

Fig. 8 vis .a detailed perspective view of .a sprocket feed wheel of theltype that may he processed in accordance with the apparatus featured inFigs. 1 `to `6, inclusive;

Fig. .Bis a .plan View ,of the principal apparatus featured in Fig. `2but modified by the .addition of a different supporting Aspindle for.processing a .piece .partsuch as that featured in Fig. .'I .and Vhaving.also a diilerent type of gear .ratio in con` nection with .thesupervisory control shafts;

Fig. l0 is .a fragmentary sectional detailview of one form of end mill.cutter .des'ignedtoproduce sprocket wheel teeth of substantially.cylindrical formation with semispherical turrets, and Fig. 11 is afragmentary sectional detail view corresponding to that of Fig. 10 butfeaturing .a modified end mill cutter construction for form- .ingsprocket Wheel teeth having cylindrcalbase portions'and frusto-conicalturrets.

Referring now .more particularly to the accom? panying drawings, thereference character "IVI designates .generally a` table top y Tof a,prlllillllil Supporting structure on the surfaceo which visorycontrolunit isa rotary; Vshaft l.I4 which is continuously driven by themotor I5 through the instrumentality of a longitudinally displaceable ltongue and groove coupling I6 that permits the advancement andretraction of shaft I4 to and from the locus of the work generallydesignated I 1 in which the sprocket wheel blank is supported during themachining operation.

The work indexing unit is supported upon its own baseplate I2 which isprovided with `slots I8 parallel to each other so as to render the baseplate adjustable 4upon the machine bed 'IVI `in aV direction parallel tothe indexing spindle, Figs. l2 and 9. Upon proper placement, the baseplate I2 is secured to the principal bed Il by means of the' tighteningbolts I9 which are Screw threaded into 'openings of thetable top II. Ina similar mannenthe base plate I3 of thesuper- 4visory control 'unit iscorrespondingly adjustfable in Va direction perpendicular-to theindexing shaft axis of rotation but longitudinal to the Y axis of itsown shaft, it being provided with slots j2I 'an'd correspondingtightening bolts 22. The

vvregulation of block|2 is accordingly longitudinaly of its indexingshaft 29`tov enable the'disposition of the sprocketV feed blanklongitudinally of its shaft.- while `Y adjustment of block I3 varies thedepth of movement of the hollow mill holding shaftA I4, and itsintegrally associated spindle Vch'1'1ck`l3.-l j

- In accordance with a method of processing tape feed sprockets carriedupon solid spindle shafts 24, which are of the type featured in Fig.j8,one end is secured withinkthe clamping Yjaws of a collet Y25, Fig.- 5,while therother end, which is conically Arecessed,vreceives a conicalcenter set screw 26 to secure it. Thus, support is afforded to bothextremities of the shaft 24, as the sprocket'whreel 21 is held inalignment with Ythe axial center of thecutting tool 28Figs..2f and""6. v

When inserting this typer of piece part into the machine, the. end ofYshaft 2'4 which is clamped tooth 3,5 is released vto impart a clockwiserota',-

tion to V the ratchet wheel 34 by impingement against `an inclinedsurface of one of its teeth until the radialtooth surface of thediametri'- callyopposite ratchettooth cornesV into `abuttingrelationship with the xed locating plate! tooth :33. The rigid andpivoted teeth of locating plate "32,Y described above, serve to align`the workpiece 2'4 radially so thatthereafter the sprocketieedteethformed ondisc 21 will have a definite relationship in radial.disposition with respect 'to the ratchetwheelteeth ofthe VratchetYwheel 34. vAfter thisalignment is thus Yestablished the longitudinallocating set `screw 26Y isturned in by vvingassemblyl designated Vas'43.i j

thev inwardly extending portion of the workpiece 24 as clearlyillustrated in Fig. 5.

The collet 25 is contained within the tubular tapered sleeve 31 whichhas drive fitted relationship with the frictionally driven hollowindexing *i shaft 38, journaled in a bushing 39vof a principalsupporting block 4I and providedwith an end viiange 42 vfor pressureagainstganiendsthrust' bear- The'hollow shaft 38 has a threaded portion44 which receives a notched detent wheel 45, held in` place thereon bythreaded collars securable by set screws 46 so as to be integral withsaid shaft 38. At 41 the indexing shaft is reduced in diameter andbetween the shoulder afforded thereby and a xed collar 48 are disposedtwo control discs generally designated 49 and 5I. Disc'5l is' providedwith a single peripheral notch, asV shown in Fig. 4, while disc 49 isprovided with a number of peripheral notches in accordance lwith theparticular. piece of work to be processed. VIn the class of sprocketWheel manufacture, illus` ytrated in Figs. 1to 5, inclusive, there arevcontemplated twelve sprocket wheel teethinwheel 21 so that accordinglythere are providedtwelve equally spacedperipheral notches inthe controldisc 49. y y Y At the left of the plate or disc l4,8 there is a drivenworm wheel 52 situated between twov adjacent cork slip discs or washers53 and anadjustment nut 54 supplemented by a'check nut 555servesithrough artension spring'dis'c 56to apply end thrust pressure tofrictionally confine the drivenworm wheel 52A between its frictionallyyielding driving discs 53. w y A Y Power for imparting rotation to thedriven worm wlieel 52 is obtained .from a synchronous indexing motorv51,Figs. 2 and 4, which drives the vertical shaft 59 carrying the wormwheel 6I through a gear reduction box 58. Electrical supervision overindexing motor 51, which drives i wheel 52, is had by a microY switch62, Fig. 41. As may be noted from Fig. 1, the closure of "contact pair62 by a control cam 83- (Figs. 2 and 3)' com'- pletes a circuit frompower source which energizes not only the indexing motor '51but also theindex release magnet 65, which magnet'lin attractingY its Varmature (notshown) 'moves'pull rod 66 downwardly, Fig. 3, leverv61 to be rotatedclockwise about its pivot 68,"and accordingly detent bar 69 tobe'withdrawn from engagement within one of the knotches of index wheel`45.

It will be noted from Fig. 1, that'Y contactpair E2 is situated inelectrical parallelism-with anl-V other micro switch contactpairdesignated 1I, so that upon the closure of either one of these pairsof contactsfthe circuit is completed' from current source terminal 12over conductor 13, thence either over branch conductor 14 and contactpair 1I to the junction point 15,- or over the Y branch conductor 16through contact pair 62 to integrally associated with a gear reduction.box`

a vknurledy head 36.v The collet ,drawl nut 3| is Y :thenzvitightenedtocause colletr 25 to'rmlgrasp the junction point 15. Thereafter thecircuit is traceable over conductor 11 through the winding of magnet 65and motor 51 in parallel, return which performance is underthe'supervision of a lever 8I pivoted at 82 and controlled by the indexsupervisory cam 83 which is one of two supervisory cams rotated by thespindle feed motor'l 84,1Figs. 1, 2,- and 3. The spindle feed motor. is

l85 through which power is supplied to thejgear ireintomprised 0f gears86 and 81- Beneath cem agregue $3 and 'gear 1 .as best :revealed in Eig.3, .fis lanother cam designated 8B having linvolute pro- 'i'le .anddesigned tobe effective upon the .adda-- is terminated with 'a disc 19.2that dwells within an annular recess 93 in the enlargedportion of shaft14- A.In accordance Awith the effect of vcam Y88, whose faction isresisted by .the ycompression spring :94, .shaft .I 4 :is .thrustleftwardly `or is permitted .to return irightvvardly as designated indotted and solid outline, Fig. f6.

'Ilhe uppermost .rcam .'83,acting as it does :upon .lever :81, 'causesthe closure :of contact pair 62 .at a precise interval during yeachrevolution of `cam shaft 112s coinciding With .the advancement .of theindex wheel 45 as determined by the effect of cam 54:9 iupon the micro'switch FH, .'Fig. 4. As the vcam 83 rotates counterclockwise, itrepeatedly .actuates lever arm 8l causing the `contact pair 52 tofbeclosed, energizing the withdrawal magnet 65 whichffreestheindexratchet wheel 45 and at the 'same time v-energizes index motor5l. The :effective yenergizing pulse imparted by the cam 83 is of shortduration, however, andas a consequence vof the rotation of :individualindexing'cam i9 whose counterclockwise rotation from` one dwellposition, Fig. 4, to `a succeeding one depresses button 53, there isl'closed the micro switch 1|. As :a result of the Vclosure of switch1l., Fig. 1, the circuit which had been but momentarily `completed bythe contact pair 52 is `maintained by the Contact pair il. Accordingly,motor 5l and magnet 55 will continue to be energized OI the periodcontact pair "H remains closed. This period will vvary in accordancewith the particular provisions of disc 4).

.As Acontemplated in the -showing -of Figs. l to 5,

inclusive, disc 49 is provided with twelve lperiphf eral notchesillustrated in Fig. 4.. As each suoceeding one of the notches encountersthe follower arm 54 .it permits the lspring `t-ensioned button 53 todispose said arm as illustratedin this iigure,

:and the contact pair ll'l vwill then be permitted to open arresting thefurther operation of motor 5l and de-energizinglelay 55.' As a result ofthe de-energ-ization of relay 65, spring .95, Fig. 3, will .eiectivelyrestore the train of levers and rods .66, 61, to the positionlillustrated in Fig. 3 "where- .at the detent plunger 'E9 will settleinto one of the .notches of the .master indexing Adisc 45 accu ratelylocating shaft 38.

Thereafter and for the major portion of each cycle as indicated bythelow area of cam Y83, Fig. f-

2, the index shaft, Figs. 5 and 10, remains dor mant and the millingshaft i4 is moved lef-twardly, Fig. 2, by the action of camii, Fig. 3,upon bell crank 3S. In consequence, the milling tool 9J.,

Figs. 6 and 10, will shape .a cylindrical tooth 98 The journal block.9.9, see especially Fig.. 6, isY

provided with two bearing ysleeves Iii! and 52 which support the millingshaft .I for limited longitudinal and free rotary movement.. At itschuck extremity, ,shaft |11` is somewhat enlarged may Ybe regulated byadjusting and threaded asat i113, :for receiving the :notasonailchucknut 2104. :The end tof :shaft I 4 is bored internally ito :afford a'conical 4recess-,of vsuitable taper to conform with that oit aissplitcollet i115. The collet L05 is shou'lderedsas iat y|06 and-:thereat.receives :binding ,.pressureefrom the* end 'rwali l0] fof nut 1h04;`2W-henthe nut HM fisjdrawnlrmf ly .in position the end thrust :eff-ectupon collet M5 causes fthe :latter .member .to be iconstricted and togrip the milling tool :91 holding the flatter member Lin integralrelationship with the :shaft i4.

The axial :center of the :milling machine shaft i4 is in horizontalalignment with :the Icorresponding center V of fthe indexing shaft,Lllig. i6. Accordingly, all of the teeth `B8 :formed bythe hollowmillingatool -9-1 :will therefore :be radially disposed and will be :spacedangular-ly .about the wheel 2.71 in accordancewith the adjustment provided bythe indexing mechanism just described.

.In placing the I'piece .part 24 fFig. 6, Ainto .the locating plate:32,it will-be `recalle'dthai, .its radial position is attained :by the'rotary effect yof movable pawl 35 so :that one of the teeth on sprocketwheel 134 -comes into abutting engagement with the stationary locatingvplate kdog `designated 33.. In this way, the formation 0f the sprocketwheel teeth 98 is accurately established with respect to the radialdisposition of .the .ratchet Wheel teeth 34.

Means have been provided asbest illustrated in Figs. ..2 .and 3 forsupplying acontinuous stream of coolant to the piece part as itundergoesmachining operation. For Athis purpose, a .run-off trough Hi8 isdisposed beneath the sprocket wheel 2l at; an inclination so that its.lowermost extremity is Situated directly above a residue settling tank|09. Coolant discharged from the end of .nozzle VI I of the flexiblesupply tube M22 vmay be directed onto the piecepart undergoing :millingoperations and therefrom the coolantwill` latter device may be `of anytype .suitable in the service vof circulating coolant'fluid and isoperated by an electric motor Idesignated -H 6 iin Figsi andv 3. Thecoolant fluid .is forced upwardly through a -`supply `pipe y'I l .-1 andthevolume of the stream the flow regulating Icock* '-i i8. l Y

The apparatus thus farfdisclosed is particularly adapted to theformat-ion by .milling vof sprocket feed teeth -on :an .apparatus havingthe general configuration ras .illustrated in Fig. ^`8 and designed tobe .provided with Itwel-Ve equally spacedperipheral teeth v58 ofcylindrical body formation with semispherical heads :usedfin thestep-by-step advan'cernent` of I'perforated tape in' varioustypes ofprinting -teiegrajph apparatus. In the advancing of other Iclasses ofperforated control forms, various types of y:feed -.-sprocketsdifferingspe.- cically from that described above may fbe encountered. 1

In Fig. 57 there is illustrated anexample lof va sprocket feedwheelfzinl Ywhich ithe. number :of teeth Vexceeds that contemplated 4inFig. 1:8 and to which there is provided no support suchas the solidintegral shaft :of piece parts'fZL .It-is to`be noted, moreover, that:the teeth provided in .this embodiment :are preferably formed :withspherical :lower shank portions :and frusta-conical radial describedcertain embodiments of a supporting fixture apparatus which may beapplied to the .principalV device described above and thereby adapted tothe holdingof the piece part and op# erating of the indexing mechanismtofaccommo- -datethe requirements of themodifcation, Fig. 7. f Referringnow particularly to Fig. 9, attention is directed to the internallytapered driving sleeve or shaft 38 which is provided with the endthrust'flange 42 as in the preferred adaptation. Into this member thereis drive fitted a plug |2|l so that the two rotate in unison. The plug|20 is shaped to afford an enlarged or head portion ||9 lwhich fitswithin the -recess |2I -of the sprocket feed wheel |22 shown in Fig. 7.

In the formation ofthe blank for making this type of apparatus, acentral ridge, Fig. l1, is turned 'corresponding tov vthe alignment `ofsprocket feed teethY |23. .1 A kthreaded stub shaft |24 integral withthe plug |28 extends through the opening |25 ofintegr'al collarformation |26. In order -to secure the blanks rmly upon the holding plug|20, a tightening nut |21 is used having radial spindle -arms to affordample grip. Since there is provided no ratchet wheel associated withthis type of feed sprocket, it is not essential to effect the accurateradial alignment of Vvthe blank as was the case with the first 'defscribed embodiment. t Y y -Preferably forty-eight feed teeth |23 areformed in this type of workpiece so that accordingly the particularcontrol disc utilized in this operationdesignated 490 is provided withfortyeight peripheral notches instead of but twelve i as was the case inconnection with the first em-V bodiment control disc 49. In addition tothe foregoing change-over which consists in applying the modifiedcontrol disc 498 and the solid plug holding device |20, it Vhas beenfound'expedient to increase the peripheral speed of the timing cams onshaft |29, since the ma` terial used in the manufacture of pieceV partsil# lustrated in Fig. 7 need not be of the hardness during processing asthat of the piece part fea` tured in Fig..8. Accordingly, the drivinggear 860 which receives itspower Vfrom the motor 84 ispreferably largeras compared with the driven gearr83|l than inthe case of the driving anddriven gears 86 and 83 in Fig. 2.

Under bothA practices, it is kdesirable to execute 'extremities Yorturret portions. There will now be Y switch r|39 is providedwhichvbridges across and therefore parallels contact VpairY |3|. The manualcontrol'switch is operated but momentarily l the contact switch |3|, thelatter continues to rea 'full revolution comprising either twelve or Yforty-eight separate machining operations on thev peripheries of pieceparts such as that indicated in Figs. 8 or 7 and thereafter to bring theindexing shaft,'vFig. 5, to rest to await replacement by the operator.,Accordingly, there has been provided a supervisory control switch |3|which is located in a circuit'for energizing the milling machine spindlemotor as well as the supervisory control motors |5 and'84, respectively.This cir`- cuit is traceable from one terminal '|2, over lines 13 and|32, to a manual control switch |33 which is closed during the time thatthe machine is in operation, over line |34 through the contact pair|31', afore-mentoned, thence over line |35 to the junction point |36.From here the circuit is par-Y alleled through the windings of motors 84and l5 joining again at junction |31, thenceV over rent to the motors|5and 84. As an alternative tov contact kpair,` l3l, however, a vmanualstart main closed until this disc 5| has undergone a complete revolutionand the notch |4| again registers with the follower |42 permitting thelatter member to resume the position indicated in.Fig. 4, and openingthe start circuit of motors |5 and 84.' 'Meanwhile however, the operatorwill open switchl39 so that the break by disc 5| of the contact pair |3|will arrest current to the control motors.

'It will be recalled that motor 84 exercises con- Y trol over ca'm shaft|29 which V.carries the two` to restarting under supervision of manualcontrol Y switch |39.

In Fig. 3 there will be noted a convenient control panel designated |44through which there extends the manipulation 'handles for switches |33Vand |39 already described, as well as of a further switch |45 whichcloses a local circuit for operating the coolant circulating motor H6.Under normal conditions of operation switches |33 and |45 remain vclosedbut switch |39 is opened as soon as the spindle has loeen permitted torotate a suflcient distance Vfor notch |4| to ride out of range of thefollower |42 as just described.

In the type of mill used in the formation of spherical terminatingsprocket wheel teeth, the cutters are preferably two in number indicated|58, Fig. l0, and formed by milling out longitudinally as at |5|radially opposite quadrants with an intermediate profiled section |52which resembles the sprocket tooth outlined as may be compared in thisillustration. The end mills ofthe cutter featured in` Fig. ,1v1 differfrom each other in one respect, notably that tooth |53 is provided witha longitudinal cutting edge par- Yalleling the axis of rotation voi' thecutter while the other tooth is provided with a diagonal cutting edge|54 for forming the frusto-conical sprocket wheel tooth extremities asVbest indicated in Figs. 7 and 11.

Having Ydescribed the present invention with reference toa particularembodiment, it will be noted that numerous modications and vari-V In acontrol system' for automatically Ymilling circular Work pieces, anindexing spindle comprising means for intermittently rotating a blankthrough predetermined angular distances, a pair of-control discs carriedon said spindle, one of said discs having a single peripheral notch andVthe other of said discs having a plurality of peripheral notches/equalin number to the num# ber of operations to be performed on the peripheryof said work piece, an electrical circuit arrangement, contact means insaid circuit for initiating milling operations, means eiective pursuantto ytheoperation of said contact means for controlling the regularrecurrence of said milling operations comprising a switch, a, cyclicallyoperable cam for operating said switch, a master indexing deviceelectrically controlled byl said switch, and further electrical meanscontrolled by said pair of control discs, whereby under the supervisionof said notches in said pair of control discs said further electricalmeans is eifective to control said means for controlling the regularrecurrence of said milling operations.

VICTOR GREY.

Vli

l0 REFERENCES CITED The following references are of record in the fileof this patent:

UNITED STATES PATENTS

